Industrial wastewater treatment system capable of stabilizing discharged water quality and control method thereof

Abstract

The invention relates to an industrial wastewater treatment system capable of stabilizing discharged water quality and a control method thereof, and belongs to the field of wastewater treatment. The system comprises a pretreatment module, a primary biochemical treatment module, a secondary deep treatment module, a reuse water module, an aeration module, a dosing module, a sludge collection module, a sludge drying module, a flow control module, a dosing control module, a dissolved oxygen control module, an internal circulation control module, an external reflux control module, a sludge discharge control module and a backwashing control module. A water quality parameter collection module and a central control module. According to the invention, through multi-factor cooperative control, the control of the system on a single variable in the wastewater treatment process is more comprehensive than single-factor control; through effective wide-range control, the action frequency of an actuator of the system is reduced, and the service life is prolonged; the variable multi-stage biochemical reaction tank capable of being flexibly adjusted is adopted, and multi-layer backflow adjustment is adopted, so that the system can change an intermediate treatment process, and the adaptability and the reliability of the system are improved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to an industrial wastewater treatment system with stable discharge water quality and a control method thereof. Background Art

[0002] Industrial wastewater refers to various wastewaters generated during industrial production (e.g., wastewater from medicine, dyes, coatings, cosmetics, additives, etc.), which contain many types of complex and difficult-to-degrade pollutant components, such as organic solvents, petroleum compounds, phenols, alcohols, etc. At present, some industrial wastewater treatment systems only monitor a single process indicator (e.g., only control a single factor such as aeration volume, acid / base dosage, water pump flow rate, etc.), and do not have a systematic and comprehensive control strategy. There are also some industrial wastewater treatment systems whose control systems are too precise and too sensitive, and whose reaction range is too narrow, which instead produces a certain "inflexibility", causing the actuator to move very frequently and easily cause damage, and then may cause the entire system to collapse. CN114477432A discloses an automatic control system and method based on sulfur autotrophic denitrification. Although the treatment method and system use sulfur autotrophic deep denitrification to treat wastewater and achieve a good treatment effect, the restriction range of the raw water quality and the pH value of the intermediate process is too narrow, and the method only cares about the process indicator of pH value in the control process, lacks control of other influencing factors. CN115231743A discloses a low-cost desulfurization wastewater treatment method and system. Although the wastewater treatment method and system can achieve zero discharge of desulfurization wastewater, the process indicators are strictly required during the treatment process and the control range is too narrow, which will inevitably lead to a higher frequency of actuator action in the system and a reduced life of the system actuator.

[0003] In addition, some manufacturing companies that produce according to orders and have a fast product replacement cycle have large fluctuations in wastewater quality due to the rapid changes in the types and composition of the wastewater they produce. Traditional industrial wastewater treatment systems are often composed of a number of single-function treatment units. After the design and construction, it is difficult to change the intermediate treatment process. If the wastewater to be treated changes significantly, the traditional industrial wastewater treatment system will be difficult to adapt quickly. Summary of the invention

[0004] The purpose of the present invention is to provide an industrial wastewater treatment system and a control method thereof for stabilizing the discharge water quality in order to overcome the defects of the above-mentioned prior art. The present invention proposes a new coupling coordination method combining multi-factor coordinated control with single-factor robust control. Based on this, a new technical scheme is proposed. The automatic control system does not control a certain operating process parameter, but focuses on controlling the key water quality indicators of the wastewater, such as COD, ammonia nitrogen, total phosphorus, total nitrogen, etc. At the same time, a small number of key operating parameters of the wastewater treatment system operation process are also controlled, but the control range is greatly relaxed.

[0005] The present invention can be implemented by the following technical solutions:

[0006] The first object of the present invention is to provide an industrial wastewater treatment system with stable discharge water quality, the industrial wastewater treatment system comprising a wastewater treatment device, a sludge treatment device and a system control device; the wastewater treatment device comprises a pretreatment module, a primary biochemical treatment module, a secondary deep treatment module, a recycled water module, an aeration module, and a dosing module; the sludge treatment device comprises a sludge collection module and a sludge drying module; the system control device comprises a flow control module, a dosing control module, a dissolved oxygen control module, an internal circulation control module, an external reflux control module, a sludge discharge control module, a backwashing control module, a water quality parameter collection module, and a central control module; the wastewater treatment device is connected to the sludge treatment device; the sludge treatment device is connected to the system control device; the wastewater treatment device is connected to the system control device.

[0007] Furthermore, the pretreatment module is connected to the primary biochemical treatment module; the primary biochemical treatment module is connected to the secondary in-depth treatment module; the secondary in-depth treatment module is connected to the recycled water module; the secondary in-depth treatment module is connected to the sludge collection module; the sludge collection module is connected to the sludge drying module; the aeration module is respectively connected to the pretreatment module, the primary biochemical treatment module, and the secondary in-depth treatment module; the dosing module is respectively connected to the pretreatment module and the sludge collection module.

[0008] Furthermore, the pretreatment module, the primary biochemical treatment module, the secondary in-depth treatment module, the recycled water module, the aeration module, and the dosing module all include a signal output terminal and a signal input terminal;

[0009] The sludge collection module and the sludge drying module both include a signal output end and a signal input end;

[0010] The flow control module, dosing control module, dissolved oxygen control module, internal circulation control module, external reflux control module, mud discharge control module, backwash control module, water quality parameter collection module, and central control module all include a signal output terminal and a signal input terminal;

[0011] The signal output ends of the pretreatment module, the primary biochemical treatment module, the secondary in-depth treatment module, the recycled water module, the aeration module, and the dosing module are respectively connected to the signal input end of the central control module;

[0012] The signal output ends of the sludge collection module and the sludge drying module are respectively connected to the signal input end of the central control module;

[0013] The signal output ends of the flow control module, the dosing control module, the dissolved oxygen control module, the internal circulation control module, the external reflux control module, the sludge discharge control module, the backwash control module, and the water quality parameter collection module are respectively connected to the signal input end of the central control module;

[0014] The signal output end of the central control module is respectively connected to the signal input end of the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module, the recycled water module, the aeration module, the dosing module, the sludge collection module, the sludge drying module, the flow control module, the dosing control module, the dissolved oxygen control module, the internal circulation control module, the external reflux control module, the sludge discharge control module, the backwash control module, and the water quality parameter collection module.

[0015] Furthermore, the signal output ends of all modules included in the wastewater treatment device are connected to the signal input end of the central control module. The signal output ends of all modules included in the sludge treatment device are connected to the signal input end of the central control module. The signal output ends of the flow control module, the dosing control module, the dissolved oxygen control module, the internal circulation control module, the external reflux control module, the sludge discharge control module, the backwash control module and the water quality parameter collection module are connected to the signal input end of the central control module. The signal output end of the central control module is connected to the signal input ends of all other modules of the system.

[0016] Furthermore, the pretreatment module mainly includes a wastewater collection tank, an accident tank, a regulating tank, a dosing stirring tank, a physicochemical sedimentation tank, a pre-oxidation tank and a pretreatment collection tank;

[0017] The accident pool, wastewater collection pool, regulating pool, dosing and stirring pool, physicochemical sedimentation pool, pre-oxidation pool and pre-treatment collection pool are connected in sequence;

[0018] The raw wastewater is introduced into the accident pool and wastewater collection pool respectively;

[0019] The primary biochemical treatment module mainly includes an anoxic tank, an anaerobic tank, and an aerobic tank group;

[0020] The anoxic tank, anaerobic tank, and aerobic tank groups are connected in sequence;

[0021] The anoxic tank is connected to the pretreatment water collection tank;

[0022] The secondary deep processing module mainly includes a variable multi-stage biochemical reaction tank and a membrane biological reaction tank;

[0023] The variable multi-stage biochemical reaction tank is connected to the membrane biological reaction tank;

[0024] The variable multi-stage biochemical reaction pool is connected to the aerobic pool group;

[0025] The membrane biological reaction tank is connected to the anoxic tank, the anaerobic tank and the aerobic tank group respectively;

[0026] The recycled water module mainly includes an intermediate tank, an ultrafiltration component, an ultrafiltration concentrated water tank and a clear water tank;

[0027] The intermediate tank is connected to the ultrafiltration component;

[0028] The ultrafiltration components are connected to the ultrafiltration concentrated water tank and the clear water tank respectively;

[0029] The ultrafiltration concentrated water pool is connected to the anoxic pool;

[0030] The intermediate pool is connected to the anoxic pool;

[0031] The clean water tank is connected to the membrane biological reaction tank;

[0032] The water discharged from the clean water tank is reused as reclaimed water;

[0033] The aeration module mainly includes a fan unit and an ozone device;

[0034] The fan group is respectively connected to the regulating tank, the aerobic tank group, the pre-oxidation tank, and the variable multi-stage biochemical reaction tank;

[0035] The ozone device is connected to a fan unit (so as to pass ozone into the pre-oxidation tank through the fan unit).

[0036] Further, the sludge collection module mainly includes a sludge collection tank group (two sludge tanks connected in series);

[0037] The sludge collection tank group is connected to the physicochemical sedimentation tank and the membrane biological reaction tank respectively;

[0038] The sludge drying module mainly includes a sludge filter press and a drying device;

[0039] The sludge filter press is connected to the drying equipment;

[0040] Transporting the dried sludge in the drying equipment outward;

[0041] The sludge filter press is connected to the pretreatment water collection tank.

[0042] Furthermore, the dosing module mainly includes a coagulant storage tank, a flocculant storage tank, an acid storage tank and an alkali storage tank; the dosing module is respectively connected to the regulating tank, the dosing stirring tank and the sludge collection tank group.

[0043] Furthermore, the flow control module mainly includes a flow meter, a liquid level meter, a water pump and a valve connected to the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module and the recycled water module;

[0044] The dosing control module includes a pH meter, a turbidity meter, a thermometer, an acid metering pump, an alkali metering pump, a coagulant metering pump and a flocculant metering pump connected to the pretreatment module, the sludge collection module and the dosing module;

[0045] The dissolved oxygen control module includes a dissolved oxygen meter connected to the primary biochemical treatment module and the secondary deep treatment module, and the dissolved oxygen control module is connected to the fan unit of the aeration module;

[0046] The internal circulation control module includes an internal circulation pump connected to the primary biochemical treatment module;

[0047] The external reflux control module includes a reflux pump connected to the secondary deep processing module and the recycled water module, and a reflux valve connected to the primary biochemical processing module;

[0048] The sludge discharge control module includes a sludge discharge pump connected to the pre-treatment module, the secondary deep treatment module, and the sludge collection module;

[0049] The backwash control module includes a backwash pump connected to the secondary deep processing module and the recycled water module;

[0050] The water quality parameter collection module includes a COD monitor, an ammonia nitrogen monitor, and a pH meter connected to the pretreatment module and the recycled water module. Furthermore, the central control module mainly includes a central control PLC and a host computer. The host computer is integrated with an intelligent control unit, which can introduce intelligent control algorithms (such as fuzzy control, neural network control, genetic algorithm, etc.), and can also remotely monitor and control the processing system through Internet technology.

[0051] Furthermore, the variable multi-stage biochemical reaction pool includes a plurality of small reaction pools, which are connected by overflow pipes, and each small reaction pool has a short pipe with a valve at the bottom of the same side connected to the reaction pool overflow pipe, and one end of the overflow pipe is connected to a drain valve and a drain pump. After completion, the number of stages of the variable multi-stage biochemical reaction pool can be increased or decreased as needed. In addition, the dissolved oxygen content of each small reaction pool can be adjusted according to demand to produce different anaerobic / anoxic / aerobic small reaction pool combinations.

[0052] Furthermore, the central control module mainly includes a central control PLC (central control PLC control cabinet) and a host computer, wherein the host computer is integrated with an intelligent control unit, which can introduce intelligent control algorithms (such as fuzzy control, neural network control, genetic algorithm, etc.), and can also remotely monitor and control the processing system through Internet technology.

[0053] A second object of the present invention is to provide a control method for an industrial wastewater treatment system for stabilizing the discharge water quality, the control method comprising the following steps:

[0054] The flow control module is used to realize the central control module to control the pump flow and valve opening of the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module and the recycled water module, and to coordinate the control of the hydraulic retention time of the water pool;

[0055] The dosing control module is used to realize the central control module to control the dosing flow and dosing time of the pretreatment module, sludge collection module and dosing module, so as to achieve the coordinated control of pH value and the coordinated control of physical and chemical sedimentation effect;

[0056] The dissolved oxygen control module is used to control the air volume and blowing time of the primary biochemical treatment module, the secondary deep treatment module and the aeration module, thereby realizing coordinated control of the dissolved oxygen content in the water;

[0057] The water quality parameter collection module is used to realize the control of the internal circulation control module by the central control module, and further control the flow and circulation time of the primary biochemical treatment module, thereby realizing the coordinated control of the internal circulation;

[0058] The water quality parameter collection module is used to realize the control of the external return flow control module by the central control module, and further control the flow and return time of the secondary deep treatment module, the recycled water module, and the primary biochemical treatment module, thereby realizing the coordinated control of the external return flow;

[0059] The central control module is used to control the sludge discharge control module, and further control the flow and sludge discharge time of the pretreatment module, the secondary deep treatment module, and the sludge collection module;

[0060] The central control module is used to control the backwash control module, and further control the flow and backwash time of the secondary deep treatment module and the recycled water module, thereby achieving coordinated control of the backwash effect.

[0061] Furthermore, the control method adopts multi-factor coordinated control and effective wide range control. Specifically, multi-factor coordinated control means that for a certain variable in the wastewater treatment process, there are multiple factors that can affect the variable, and the control part of the system coordinates these influencing factors to achieve control of the variable; effective wide range control means that, compared with single factor control, in the case of multi-factor coordinated control, the control of one of the factors can be relaxed to improve the robustness of the entire control.

[0062] Furthermore, the reflux route includes: the retentate of the membrane bioreactor tank (16) is refluxed to the primary biochemical module, the wastewater of the intermediate tank (17) is refluxed to the front end of the primary biochemical module, and the ultrafiltration concentrate of the ultrafiltration concentrate tank (20) is refluxed to the front end of the primary biochemical module.

[0063] Furthermore, the central control module has manual mode, program automatic mode and forced automatic mode for controlling all other modules of the system. When the central control PLC control cabinet of the central control module sets the mode selection switch of a certain module to manual gear, all actuator actions of the module can only be manually controlled through the corresponding buttons and switches in the control cabinet. When the central control PLC control cabinet of the central control module sets the mode selection switch of a certain module to automatic gear, all actuator actions of the module can only be controlled through the configuration monitoring screen of the host computer. At this time, the program automatic mode is entered by default, and all actuators of the module automatically act according to the set program; if the program needs to be modified in the configuration monitoring screen of the host computer, the forced automatic mode is entered, and the unmodified part is still executed according to the previous program.

[0064] Furthermore, the flow control module mainly includes flow meters, liquid level meters, water pumps and valves of the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module and the recycled water module. The output signal of the liquid level meter is used to realize the control of the water pump flow and valve opening by the central control module, and the output signals of the flow meter and the liquid level meter are used to realize the adaptive PID control of the water pump flow and valve opening by the central control module; while the output signals of the flow meter and the liquid level meter are used to realize the control of the water pump flow and valve opening by the central control module, the coordinated control of the hydraulic retention time of the water pool in the system can also be realized.

[0065] Furthermore, the dosing control module mainly includes a pretreatment module, a sludge collection module, and a pH meter, a turbidity meter, a thermometer, an acid metering pump, an alkali metering pump, a coagulant metering pump, and a flocculant metering pump of the dosing module. The output signal of the pH meter is used to realize the control of the dosing flow rate and dosing time of the acid metering pump and the alkali metering pump by the central control module, so as to achieve coordinated control of the pH value; the output signal of the pH meter, the turbidity meter, and the thermometer is used to realize the control of the dosing flow rate and dosing time of the coagulant metering pump and the flocculant metering pump by the central control module, so as to achieve coordinated control of the physical and chemical sedimentation effect.

[0066] Furthermore, the dissolved oxygen control module mainly includes dissolved oxygen meters of the primary biochemical treatment module and the secondary deep treatment module, and the dissolved oxygen control module is connected to the fan unit (21) of the aeration module. The output signal of the dissolved oxygen meter is used to realize the central control module to control the air volume and blowing time of the fan unit (21), thereby realizing coordinated control of the dissolved oxygen content in the water.

[0067] Furthermore, the internal circulation control module mainly includes the internal circulation pump of the primary biochemical treatment module. The output signals of the COD monitor and the ammonia nitrogen monitor of the water quality parameter collection module are used to realize the control of the flow rate and circulation time of the internal circulation pump by the central control module, thereby realizing the coordinated control of the internal circulation.

[0068] Furthermore, the external reflux control module mainly includes the reflux pumps of the secondary deep treatment module and the reuse water module and the reflux valve of the primary biochemical treatment. The output signals of the COD monitor and ammonia nitrogen monitor of the water quality parameter collection module and the level meter of the flow control module are used to realize the control of the flow rate and reflux time of the reflux pump by the central control module, thereby realizing the coordinated control of the external reflux.

[0069] Furthermore, the sludge discharge control module mainly includes a sludge discharge pump of a pre-treatment module, a secondary deep treatment module and a sludge collection module, and the flow rate and sludge discharge time of the sludge discharge pump are controlled by a preset program of the central control module.

[0070] Furthermore, the backwash control module mainly includes the backwash pumps of the secondary deep processing module and the recycled water module. The flow rate and backwash time of the backwash pump are controlled by the preset program of the central control module, thereby realizing the coordinated control of the backwash effect.

[0071] Compared with the prior art, the present invention has the following advantages:

[0072] 1. Due to the use of multi-factor coordinated control method, the control part of this system coordinates the multiple influencing factors of a single variable in the wastewater treatment process, making the control of the variable more comprehensive than single factor control;

[0073] 2. Due to the adoption of effective wide-range control method, the control part of this system can relax the control of a single factor among multiple factors. Furthermore, the control of a single factor can be relaxed in turn, thereby reducing the action frequency of the actuator and extending the service life of the actuator;

[0074] 3. Due to the use of a flexibly adjustable variable multi-stage biochemical reactor and multi-level reflux regulation, this system can change its intermediate treatment process after design and construction, and has a high adaptability to changes in raw water and wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 The overall framework diagram of the industrial wastewater treatment system for stabilizing the discharge water quality of the present invention;

[0076] Figure 2 This is a treatment process flow chart of an industrial wastewater treatment system for stabilizing discharge water quality according to an embodiment of the present invention.

[0077] In the figure:

[0078] 1. Accident pool, 2. Wastewater collection pool, 3. Regulating pool, 4. Dosing mixing pool, 5. Physicochemical sedimentation pool, 6. Pre-oxidation pool, 7. Pretreatment collection pool, 8. Sludge collection tank group, 9. Sludge filter press, 10. Drying equipment, 11. Dosing component, 12. Anoxic pool, 13. Anaerobic pool, 14. Aerobic pool group, 15. Variable multi-stage biochemical reaction pool, 16. Membrane biological reaction pool, 17. Intermediate pool, 18. Ultrafiltration component, 19. Clear water pool, 20. Ultrafiltration concentrated water pool, 21. Fan unit, 22. Ozone equipment. DETAILED DESCRIPTION

[0079] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0080] The present invention discloses an industrial wastewater treatment system with stable discharge water quality and a control method thereof, belonging to the field of wastewater treatment. The present invention includes a pretreatment module, a primary biochemical treatment module, a secondary in-depth treatment module, a recycled water module, an aeration module, a dosing module, a sludge collection module, a sludge drying module, a flow control module, a dosing control module, a dissolved oxygen control module, an internal circulation control module, an external reflux control module, a sludge discharge control module, a backwashing control module, a water quality parameter collection module and a central control module. The present invention uses a multi-factor collaborative control method to make the system's control of a single variable in the wastewater treatment process more comprehensive than single-factor control; the present invention uses an effective wide-range control method to reduce the system's actuator action frequency and extend the system's actuator service life; the present invention uses a flexibly adjustable variable multi-stage biochemical reaction pool in the treatment process, and has multi-level reflux regulation, so that the system can change the intermediate treatment process after the design is completed, greatly improving the system's adaptability and reliability.

[0081] Features such as component models, material names, connection structures, control methods, algorithms, etc. that are not clearly stated in this technical solution shall be deemed as common technical features disclosed in the prior art.

[0082] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements; "up", "down", "left", "right" and the like are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may change. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] It should be noted that, in the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0084] In the following examples, raw materials or processing techniques, unless otherwise specified, are conventional commercially available raw materials or conventional processing techniques in the art.

[0085] Example

[0086] This embodiment provides an industrial wastewater treatment system with stable discharge water quality and a control method thereof, including a wastewater treatment device, a sludge treatment part and a system control device.

[0087] The wastewater treatment device includes a pretreatment module, a primary biochemical treatment module, a secondary deep treatment module, a recycled water module, an aeration module, and a dosing module. The signal output ends of all modules included in the wastewater treatment device are connected to the signal input end of the central control module. Specifically:

[0088] (1) The pretreatment module mainly includes a wastewater collection tank 2, an accident tank 1, a regulating tank 3, a dosing stirring tank 4, a physicochemical coagulation tank 5, a pre-oxidation tank 6 and a pretreatment collection tank 7;

[0089] (2) The primary biochemical treatment module mainly includes an anoxic pool 12, an anaerobic pool 13, and an aerobic pool group 14 (three aerobic pools are connected in series, namely, a first-stage aerobic pool, a second-stage aerobic pool, and a third-stage aerobic pool);

[0090] (3) The secondary deep processing module mainly includes a variable multi-stage biochemical reaction tank 15 and a membrane biological reaction tank 16;

[0091] (4) The recycled water module mainly includes an intermediate tank 17, an ultrafiltration component 18, an ultrafiltration concentrated water tank 20 and a clear water tank 19;

[0092] (5) The aeration module mainly includes a fan unit 21 and an ozone device 22 (the ozone device 22 passes ozone into the pre-oxidation tank 6 through the fan unit 21);

[0093] (6) The dosing module mainly includes a dosing component 11, and the dosing component 11 includes a coagulant storage tank, a flocculant storage tank, an acid storage tank and an alkali storage tank.

[0094] The accident pool 1, the wastewater collection pool 2, the regulating pool 3, the dosing stirring pool 4, the physicochemical sedimentation pool 5, the pre-oxidation pool 6 and the pre-treatment collection pool 7 are connected in sequence; the wastewater raw water is respectively introduced into the accident pool 1 and the wastewater collection pool 2; the anoxic pool 12, the anaerobic pool 13 and the aerobic pool group 14 are connected in sequence; the anoxic pool 12 is connected to the pre-treatment collection pool 7; the variable multi-stage biochemical reaction pool 15 is connected to the membrane biological reaction pool 16; the variable multi-stage biochemical reaction pool 15 is connected to the aerobic pool group 14; the membrane biological reaction pool 16 is respectively connected to the anoxic pool 12, the anaerobic pool 13 and the aerobic pool group 14; the The intermediate tank 17 is connected to the ultrafiltration component 18; the ultrafiltration component 18 is respectively connected to the ultrafiltration concentrated water tank 20 and the clear water tank 19; the ultrafiltration concentrated water tank 20 is connected to the anoxic tank 12; the intermediate tank 17 is connected to the anoxic tank 12; the clear water tank 19 is connected to the membrane biological reaction tank 16; the water discharged from the clear water tank 19 is reused; the fan group 21 is respectively connected to the regulating tank 3, the aerobic tank group 14, the pre-oxidation tank 6, and the variable multi-stage biochemical reaction tank 15; the ozone device 22 is connected to the fan group 21; the dosing component 11 is respectively connected to the regulating tank 3, the dosing stirring tank 4, and the sludge collection tank group 8. Among them, the coagulant storage tank is connected to the dosing stirring tank and the sludge collection tank group, the flocculant storage tank is connected to the dosing stirring tank and the sludge collection tank group, and the acid storage tank and the alkali storage tank are connected to the regulating tank and the sludge collection tank group. The sludge treatment device includes a sludge collection module and a sludge drying module. The signal output terminals of all modules included in the sludge treatment device are connected to the signal input terminals of the central control module.

[0095] (1) The sludge collection module mainly includes a sludge collection tank group 8 (two sludge tanks connected in series);

[0096] (2) The sludge drying module mainly includes a sludge filter press 9 and a drying device 10.

[0097] Among them, the sludge collection tank group 8 is connected to the physicochemical sedimentation tank 5 and the membrane biological reactor 16 respectively; the sludge filter press 9 is connected to the drying equipment 10; the dried sludge in the drying equipment 10 is transported out; the sludge filter press 9 is connected to the pretreatment water collection tank 7.

[0098] The system control device includes a flow control module, a dosing control module, a dissolved oxygen control module, an internal circulation control module, an external reflux control module, a sludge discharge control module, a backwash control module, a water quality parameter collection module and a central control module.

[0099] The signal output ends of the flow control module, dosing control module, dissolved oxygen control module, internal circulation control module, external reflux control module, sludge discharge control module, backwash control module and water quality parameter collection module are connected to the signal input end of the central control module. Specifically:

[0100] (1) The flow control module mainly includes a wastewater collection tank inlet flow meter, a wastewater collection tank outlet flow meter, an accident tank inlet flow meter, an accident tank outlet flow meter, anoxic tank inlet flow meter, anaerobic tank inlet flow meter, first-stage aerobic tank inlet flow meter, second-stage aerobic tank inlet flow meter, third-stage aerobic tank inlet flow meter, variable multi-stage biochemical reaction tank outlet flow meter, membrane biological reaction tank outlet flow meter, intermediate tank outlet flow meter, wastewater collection tank outlet Water pumps, accident pool outlet pumps, regulating pool outlet pumps, pretreatment water collection pool outlet pumps, anoxic pool inlet valves, anaerobic pool inlet valves, first-stage aerobic pool inlet valves, second-stage aerobic pool inlet valves, third-stage aerobic pool inlet valves, third-stage aerobic pool outlet pumps, variable multi-stage biochemical reaction pool outlet valves, membrane biological reaction pool outlet pumps, intermediate pool outlet pumps, ultrafiltration concentrated water pool inlet valves, clear water pool inlet valves, intermediate water pool inlet pumps, clear water pool effluent pumps, and level gauges for each pool;

[0101] (2) The dosing control module mainly includes a pH meter for the regulating tank, a pH meter for the dosing stirring tank, a pH meter for the sludge collection tank group, an acid metering pump for the regulating tank, an alkali metering pump for the regulating tank, an acid metering pump for the sludge collection tank group, an alkali metering pump for the sludge collection tank group, a turbidity meter for the regulating tank, a thermometer for the regulating tank, a coagulant metering pump for the regulating tank, a flocculant metering pump for the regulating tank, a coagulant metering pump for the sludge collection tank group, and a flocculant metering pump for the sludge collection tank group;

[0102] (3) The dissolved oxygen control module mainly includes a dissolved oxygen meter for a first-stage aerobic tank, a dissolved oxygen meter for a second-stage aerobic tank, a dissolved oxygen meter for a third-stage aerobic tank, and a dissolved oxygen meter for a variable multi-stage biochemical reaction tank;

[0103] (4) The internal circulation control module mainly includes an anoxic tank internal circulation pump, an anaerobic tank internal circulation pump, a first-stage aerobic tank internal circulation pump, a second-stage aerobic tank internal circulation pump, and a third-stage aerobic tank internal circulation pump;

[0104] (5) The external reflux control module mainly includes a membrane bioreactor tank reflux pump, an anoxic tank reflux valve, an anaerobic tank reflux valve, a first-stage aerobic tank reflux valve, a second-stage aerobic tank reflux valve, a third-stage aerobic tank reflux valve, an intermediate tank reflux pump, and an ultrafiltration concentrated water reflux pump;

[0105] (6) The sludge discharge control module mainly includes the sludge discharge pump of the physicochemical sedimentation tank, the sludge discharge pump of the membrane biological reactor and the sludge discharge pump of the sludge storage tank;

[0106] (7) The backwash control module mainly includes a membrane bioreactor backwash pump and an ultrafiltration component backwash pump;

[0107] (8) The water quality parameter collection module mainly includes a wastewater collection tank COD monitor, a wastewater collection tank ammonia nitrogen monitor, an intermediate tank COD monitor, an intermediate tank ammonia nitrogen monitor, a clear water tank COD monitor, a clear water tank ammonia nitrogen monitor, an intermediate tank pH meter, and a clear water tank pH meter;

[0108] (9) The central control module mainly includes a central control PLC and a host computer. The central control PLC communicates with the host computer, and the communication connection can be a wired connection or a wireless connection.

[0109] The signal output end of the central control module is connected to the signal input end of all other modules of the system. The central control PLC of the central control module adopts Siemens S7-200SMART series and S7-1200 series PLC, model is CPUSR30 / EM-AE08 and CPU1212CDC / DC / DC6ES7212-1AE40-0XB0. The host computer of the central control module is integrated with an intelligent control unit, and an intelligent control algorithm of fuzzy-neural network control is introduced. The remote monitoring and control of the processing system is also realized through Internet technology. The specific intelligent control unit adopts the existing technology, and this application does not improve the intelligent control unit.

[0110] The central control module has manual mode, program automatic mode and forced automatic mode for controlling all other modules of the system. When the mode selection switch of a module in the central control PLC control cabinet is set to manual gear, all actuator actions of the module can only be manually controlled through the corresponding buttons and switches in the control cabinet. When the mode selection switch of a module in the central control PLC control cabinet is set to automatic gear, all actuator actions of the module can only be controlled through the configuration monitoring screen of the host computer. At this time, the program automatic mode is entered by default, and all actuators of the module automatically act according to the set program; if you want to modify the program in the configuration monitoring screen of the host computer, it will enter the forced automatic mode, and the unmodified part will still be executed according to the previous program.

[0111] When the central control module is in program automatic mode:

[0112] (1) Flow control of the system: the output signals of the flow meter and the liquid level meter are used to realize the adaptive PID control of the pump flow and valve opening by the central control module; while the output signals of the flow meter and the liquid level meter are used to realize the control of the pump flow and valve opening by the central control module, the coordinated control of the hydraulic retention time of the water pool in the system is realized;

[0113] (2) The system's dosing control uses the output signal of the pH meter to realize the central control module's control of the dosing flow and dosing time of the acid metering pump and the alkali metering pump, thereby achieving coordinated control of the pH value; the output signals of the pH meter, turbidity meter, and thermometer are used to realize the central control module's control of the dosing flow and dosing time of the coagulant metering pump and the flocculant metering pump, thereby achieving coordinated control of the physical and chemical sedimentation effect;

[0114] (3) Dissolved oxygen control of the system, using the output signal of the dissolved oxygen meter to realize the central control module to control the air volume and blowing time of the fan unit (21), thereby realizing coordinated control of the dissolved oxygen content in the water;

[0115] (4) Internal circulation control of the system, using the output signals of the COD monitor and ammonia nitrogen monitor of the water quality parameter collection module to realize the control of the flow rate and circulation time of the internal circulation pump by the central control module, thereby realizing the coordinated control of the internal circulation;

[0116] (5) External reflux control of the system, using the output signals of the COD monitor and ammonia nitrogen monitor of the water quality parameter collection module and the liquid level meter of the flow control module to realize the control of the flow rate and reflux time of the reflux pump by the central control module, thereby realizing the coordinated control of the external reflux;

[0117] (6) System mud discharge control, using the preset program of the central control module to control the flow rate and mud discharge time of the mud discharge pump;

[0118] (7) The backwash control of the system uses the preset program of the central control module to control the flow rate and backwash time of the backwash pump, thereby achieving coordinated control of the backwash effect.

[0119] The variable multi-stage biochemical reaction pool 15 in the system is divided into a plurality of small reaction pools, which are connected by overflow pipes. A short pipe with a valve is provided at the bottom of the same side of each small reaction pool, which is connected to the reaction pool transcending pipe. A drain valve and a drain pump are connected to one end of the transcending pipe. After the construction is completed, the number of stages of the variable multi-stage biochemical reaction pool can be increased or decreased as needed. In addition, the dissolved oxygen content of each small reaction pool can be adjusted according to demand to produce different anaerobic / anoxic / aerobic small reaction pool combinations.

[0120] The automatic control system does not control a certain operating process parameter, but instead focuses on controlling the key water quality indicators of the wastewater, such as COD, ammonia nitrogen, total phosphorus, total nitrogen, etc. At the same time, a small number of key operating parameters of the wastewater treatment system are also controlled, but the control range is greatly relaxed. For example, the control range of dissolved oxygen DO in the aerobic biochemical tank (aerobic tank group) is not the conventional 2.0mg / L~4.0mg / L, but is changed to 1.0mg / L~8.0mg / L, and the pH control range of the system is not the conventional 6~9, but 5.2~9.6.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those skilled in the art should understand that, although the present invention has been described in detail with reference to the above embodiments, the technical solutions of the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents, and these modifications or replacements do not exceed the protection scope of the present invention, which is determined by the attached claims.

Claims

1. An industrial wastewater treatment system with stable discharge water quality, characterized in that: The industrial wastewater treatment system includes a wastewater treatment device, a sludge treatment device and a system control device; The wastewater treatment device includes a pretreatment module, a primary biochemical treatment module, a secondary in-depth treatment module, a recycled water module, an aeration module, and a dosing module; The sludge treatment device includes a sludge collection module and a sludge drying module; The system control device includes a flow control module, a dosing control module, a dissolved oxygen control module, an internal circulation control module, an external reflux control module, a sludge discharge control module, a backwash control module, a water quality parameter collection module, and a central control module; The wastewater treatment device is connected to the sludge treatment device; The sludge treatment device is connected to the system control device; The wastewater treatment device is connected to the system control device.

2. An industrial wastewater treatment system with stable discharge water quality according to claim 1, characterized in that: The pretreatment module is connected to the primary biochemical treatment module; The primary biochemical treatment module is connected to the secondary in-depth treatment module; The secondary deep processing module is connected to the recycled water module; The secondary deep processing module is connected to the sludge collection module; The sludge collection module is connected to the sludge drying module; The aeration module is respectively connected to the pretreatment module, the primary biochemical treatment module, and the secondary in-depth treatment module; The dosing module is connected to the pretreatment module and the sludge collection module respectively.

3. The industrial wastewater treatment system with stable discharge water quality according to claim 1 is characterized in that: The pretreatment module, the primary biochemical treatment module, the secondary in-depth treatment module, the recycled water module, the aeration module, and the dosing module all include a signal output terminal and a signal input terminal; The sludge collection module and the sludge drying module both include a signal output end and a signal input end; The flow control module, dosing control module, dissolved oxygen control module, internal circulation control module, external reflux control module, mud discharge control module, backwash control module, water quality parameter collection module, and central control module all include a signal output terminal and a signal input terminal; The signal output ends of the pretreatment module, the primary biochemical treatment module, the secondary in-depth treatment module, the recycled water module, the aeration module, and the dosing module are respectively connected to the signal input end of the central control module; The signal output ends of the sludge collection module and the sludge drying module are respectively connected to the signal input end of the central control module; The signal output ends of the flow control module, the dosing control module, the dissolved oxygen control module, the internal circulation control module, the external reflux control module, the sludge discharge control module, the backwash control module, and the water quality parameter collection module are respectively connected to the signal input end of the central control module; The signal output end of the central control module is respectively connected to the signal input end of the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module, the recycled water module, the aeration module, the dosing module, the sludge collection module, the sludge drying module, the flow control module, the dosing control module, the dissolved oxygen control module, the internal circulation control module, the external reflux control module, the sludge discharge control module, the backwash control module, and the water quality parameter collection module.

4. The industrial wastewater treatment system with stable discharge water quality according to claim 1 is characterized in that: The pretreatment module comprises a wastewater collection tank (2), an accident tank (1), a regulating tank (3), a dosing stirring tank (4), a physicochemical sedimentation tank (5), a pre-oxidation tank (6) and a pretreatment collection tank (7); The accident pool (1), the wastewater collection pool (2), the regulating pool (3), the dosing stirring pool (4), the physicochemical sedimentation pool (5), the pre-oxidation pool (6) and the pre-treatment collection pool (7) are connected in sequence; The wastewater raw water is respectively introduced into the accident pool (1) and the wastewater collection pool (2); The primary biochemical treatment module comprises an anoxic tank (12), an anaerobic tank (13), and an aerobic tank group (14); The anoxic tank (12), the anaerobic tank (13), and the aerobic tank group (14) are connected in sequence; The anoxic tank (12) is connected to the pretreatment water collection tank (7); The secondary in-depth treatment module comprises a variable multi-stage biochemical reaction pool (15) and a membrane biological reaction pool (16); The variable multi-stage biochemical reaction tank (15) is connected to the membrane biological reaction tank (16); The variable multi-stage biochemical reaction pool (15) is connected to the aerobic pool group (14); The membrane biological reaction tank (16) is connected to the anoxic tank (12), the anaerobic tank (13), and the aerobic tank group (14) respectively; The recycled water module comprises an intermediate tank (17), an ultrafiltration component (18), an ultrafiltration concentrated water tank (20) and a clear water tank (19); The intermediate tank (17) is connected to the ultrafiltration component (18); The ultrafiltration component (18) is connected to the ultrafiltration concentrated water tank (20) and the clean water tank (19) respectively; The ultrafiltration concentrated water pool (20) is connected to the anoxic pool (12); The intermediate tank (17) is connected to the anoxic tank (12); The clean water tank (19) is connected to the membrane biological reaction tank (16); The aeration module comprises a fan unit (21) and an ozone device (22); The fan group (21) is respectively connected to the regulating tank (3), the aerobic tank group (14), the pre-oxidation tank (6), and the variable multi-stage biochemical reaction tank (15); The ozone device (22) is connected to the fan unit (21).

5. An industrial wastewater treatment system with stable discharge water quality according to claim 4, characterized in that: The sludge collection module comprises a sludge collection storage tank group (8); The sludge collection tank group (8) is connected to the physicochemical sedimentation tank (5) and the membrane biological reaction tank (16) respectively; The sludge drying module comprises a sludge filter press (9) and a drying device (10); The sludge filter press (9) is connected to the drying equipment (10); The sludge filter press (9) is connected to the pretreatment water collection tank (7).

6. An industrial wastewater treatment system with stable discharge water quality according to claim 5, characterized in that: The dosing module is respectively connected to the regulating tank (3), the dosing stirring tank (4), and the sludge collection tank group (8).

7. The industrial wastewater treatment system with stable discharge water quality according to claim 1 is characterized in that: The flow control module includes a flow meter, a liquid level meter, a water pump and a valve connected to the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module and the recycled water module; The dosing control module includes a pH meter, a turbidity meter, a thermometer, an acid metering pump, an alkali metering pump, a coagulant metering pump and a flocculant metering pump connected to the pretreatment module, the sludge collection module and the dosing module; The dissolved oxygen control module includes a dissolved oxygen meter connected to the primary biochemical treatment module and the secondary deep treatment module, and the dissolved oxygen control module is connected to the fan unit of the aeration module; The internal circulation control module includes an internal circulation pump connected to the primary biochemical treatment module; The external reflux control module includes a reflux pump connected to the secondary deep processing module and the recycled water module, and a reflux valve connected to the primary biochemical processing module; The sludge discharge control module includes a sludge discharge pump connected to the pre-treatment module, the secondary deep treatment module, and the sludge collection module; The backwash control module includes a backwash pump connected to the secondary deep processing module and the recycled water module; The water quality parameter collection module includes a COD monitor, an ammonia nitrogen monitor, and a pH meter connected to the pretreatment module and the recycled water module.

8. The industrial wastewater treatment system with stable discharge water quality according to claim 1, characterized in that: The variable multi-stage biochemical reaction pool includes a plurality of small reaction pools, which are connected by overflow pipes. A short pipe with a valve is provided at the bottom of the same side of each small reaction pool and is connected to an overflow pipe of the reaction pool. A drain valve and a drain pump are connected to one end of the overflow pipe.

9. A control method for an industrial wastewater treatment system with stable discharge water quality as claimed in any one of claims 1 to 8, characterized in that: The control method comprises the following steps: The flow control module is used to realize the central control module to control the pump flow and valve opening of the pretreatment module, the primary biochemical treatment module, the secondary deep treatment module and the recycled water module, and to coordinate the control of the hydraulic retention time of the water pool; The dosing control module is used to realize the central control module to control the dosing flow and dosing time of the pretreatment module, sludge collection module and dosing module, so as to achieve the coordinated control of pH value and the coordinated control of physical and chemical sedimentation effect; The dissolved oxygen control module is used to control the air volume and blowing time of the primary biochemical treatment module, the secondary deep treatment module and the aeration module, thereby realizing coordinated control of the dissolved oxygen content in the water; The water quality parameter collection module is used to realize the control of the internal circulation control module by the central control module, and further control the flow and circulation time of the primary biochemical treatment module, thereby realizing the coordinated control of the internal circulation; The water quality parameter collection module is used to realize the control of the external return flow control module by the central control module, and further control the flow and return time of the secondary deep treatment module, the recycled water module, and the primary biochemical treatment module, thereby realizing the coordinated control of the external return flow; The central control module is used to control the sludge discharge control module, and further control the flow and sludge discharge time of the pretreatment module, the secondary deep treatment module, and the sludge collection module; The central control module is used to control the backwash control module, and further control the flow and backwash time of the secondary deep treatment module and the recycled water module, thereby achieving coordinated control of the backwash effect.

10. The control method of an industrial wastewater treatment system for stabilizing discharge water quality according to claim 9, characterized in that: The control method adopts multi-factor coordinated control and effective wide-range control.

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